-LRB- CNN -RRB- -- The retrial of Egypt 's former president , Hosni Mubarak , on charges of killing protesters during the country 's 2011 revolution and profiteering resumed Saturday before being adjourned until next month .

Mubarak was forced from office in February 2011 following two weeks of mass street protests .

Following a lengthy trial , he and his former interior minister , Habib al-Adly , were found guilty and sentenced to life in prison last year on charges that they were complicit in the protesters ' killings .

After appealing their convictions , they were granted a new trial early this year .

Six of Mubarak 's former security aides last year were acquitted of charges related to the killings , and Mubarak 's two sons -- Gamal and Alaa -- were acquitted of corruption charges .

But they , too , were ordered to be retried after President Mohamed Morsy , himself ousted this week , ordered a new investigation last year .

Mubarak and the other defendants have pleaded not guilty to all charges .

Mubarak was present in court Saturday for the fourth session of the retrial , wearing his signature sunglasses . He made his first court appearance in May .

The retrial has been adjourned until August 17 , the prosecution said in a statement .

A public prosecutor sent Mubarak -- who spent months detained in a military hospital -- back to prison in April .

Mubarak 's health has been a bone of contention during his trial and incarceration . He suffered a heart attack after relinquishing power and had maintained that he was physically unfit to stand trial .

Mubarak has been held since his guilty verdict last year .

He is also charged with seizing public funds and misusing political influence . He also faces a corruption charge that was not part of the original trial . Mubarak is accused of selling natural gas to neighboring Israel for prices below fair market value .

The ousted autocratic leader spent three decades in charge of Egypt , the most populous Arab country .

Journalist Adam Makary contributed to this report .

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NEW : The retrial of former President Hosni Mubarak is adjourned until mid-August

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The retrial is being held for Mubarak and his sons , as well as a former minister and security aides

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Mubarak was forced from office in February 2011 following two weeks of mass street protests

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Mubarak was convicted last year but was granted a retrial after appealing his conviction